That's a fair point, but I think it actually *improves* the argument for better helper functions, since we can have them automatically invoke shlex.quote() on all of the arguments:

    def _shell_format(cmd, args, kwds):
        args = map(shlex.quote, args)
        kwds = {k:shlex.quote(v) for k, v in kwds}
        return cmd.format(*args, **kwds)

    def _invoke_shell(func, cmd, args, kwds):
        return func(_shell_format(cmd, args, kwds), shell=True)

    def format_shell_call(cmd, *args, kwds):
        return _shell_format(cmd, args, kwds)

    def shell_call(cmd, *args, **kwds):
        return _invoke_shell(subprocess.call, cmds, args, kwds)

    def check_shell_call(cmd, *args, **kwds):
        return _invoke_shell(subprocess.check_call, cmds, args, kwds)

    def check_shell_output(cmd, *args, **kwds):
        return _invoke_shell(subprocess.check_output, cmds, args, kwds)